JP2001101933A - Low temperature flexible cable - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a low temperature flexible cable that shows a low heat release in a freezer and maintains sufficient flexibility at a low temperature of -50 deg.C and below. SOLUTION: A low temperature flexible cable 1 capable of being bent at a low temperature of -50 deg.C and below comprises a plurality of insulated covering-conductors 3 formed by insulating covering wires 2 that are bundled to form cores 6 and a sheath 4 with braided structure formed by coldproof metals on the periphery of the cores 6.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a low-temperature flexible cable used for mobile equipment in a freezer below -50.degree.

[0002]

2. Description of the Related Art Conventional freezers generally have a temperature of -50.degree. C. or less, and low-temperature flexible cables that can be bent even at low temperatures are used for automatic transport equipment such as stacker cranes and traversing carts for working in the refrigerator. I have.

As a low-temperature flexible cable, 2PNCT (ethylene-propylene rubber (EPR)) having excellent cold resistance is used.
Insulated chloroprene sheath cabtire cable), 2
CT (natural rubber insulated natural rubber sheathed cabtire cable) is common.

[0004] In a freezer below -50 ° C which has begun to be built in recent years, the sheath made of conventional natural rubber, ethylene-propylene rubber (EPR) or chloroprene is insufficient in cold resistance, and may cause brittle fracture. There is.

[0005] For this reason, a method is used in which a constant temperature is applied to the core of a low-temperature flexible cable to keep the cable warm (in place of a heater wire).

[0006]

However, in this case, there are problems that the cable cannot be replaced and that the capacity of the refrigerator needs to be increased in consideration of heat radiation from the cable.

[0007] As shown in FIG. 4, a core 31 is formed by twisting bare conductors 30, and an extruded insulating layer 32 made of resin is provided on the outer periphery of the core 31. A metal braid 33 is formed on the
There is also a technique (Japanese Utility Model Publication No. Sho 53-33804) for improving the cold resistance of such a material, but there is a problem that sufficient flexibility cannot be obtained.

Accordingly, an object of the present invention is to provide a low-temperature flexible cable that solves the above-mentioned problems and has low heat radiation in a freezer and can maintain sufficient flexibility even at a low temperature of −50 ° C. or less. It is in.

[0009]

SUMMARY OF THE INVENTION In order to achieve the above object, the present invention relates to a low-temperature flexible cable which can be bent at a low temperature of -50.degree. C. or less. The core is formed by bundling these insulated conductors, and a sheath having a braided structure made of a cold-resistant material such as metal is formed on the outer periphery of the core.

The low-temperature flexible cable has a low resistance to bending because the insulated conductor moves freely in the sheath when bent, and maintains sufficient flexibility even at a low temperature of -50 ° C. or lower. be able to. Further, since there is no need to constantly supply power, heat radiation in the freezer can be minimized.

It is preferable that the sheath is formed in two layers, one of which is formed of a metal wire, and the other is formed of a cold-resistant fiber made of polyamide fiber or the like.

Alternatively, the sheath may be formed by blending a metal wire and a cold-resistant fiber made of polyamide fiber or the like.

[0013]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings.

As shown in FIG. 1, a low-temperature flexible cable 1
Is composed of a plurality of insulated conductors 3 formed by applying an insulation coating to the conductive wire 2 and a braided sheath 4 formed on the outer periphery of a bundle of these insulated conductors 3.

The insulated conductor 3 is made of polyethylene (PE)
Having a coating layer 5 composed of Polyethylene is -50 ° C
Since it becomes hard under the following low temperatures, the low-temperature flexible cable 1
Not suitable for the sheath 4 that predominantly determines the flexibility of
It is sufficiently thinner than the diameter of the low-temperature flexible cable 1 and can be sufficiently used as an insulator of the conducting wire 2 which does not significantly affect the flexibility of the low-temperature flexible cable 1.

The insulated conductor 3 is twisted so as to leave the center of the low-temperature flexible cable 1 to form a core 6. When the cable 1 is bent, the insulated conductor 3 is placed in the sheath 4. Each can move freely without interfering with each other.

[0017] The sheath 4 is formed of metal, and in particular, is formed by braiding a flexible soft copper wire.

The sheath 4 is covered by the core 6 with some allowance so that the insulated conductor 3 inside can be freely moved at the time of bending.

The operation will be described.

When a force in the bending direction acts on the low-temperature flexible cable 1 at a low temperature of -50 ° C. or less, each of the insulation-coated conductors 3 forming the core 6 of the low-temperature flexible cable 1 moves in a separate manner. It is easily bent together with the sheath 4. This becomes more remarkable as the diameter of the low-temperature flexible cable 1 increases.

At this time, since the sheath 4 is formed by braiding the soft copper wire, the sheath 4 is bent without difficulty while changing the interval between the braided soft copper wires.

As described above, the conductor 2 is coated with the insulation to form a plurality of the insulation-coated conductors 3, and the insulation-coated conductors 3 are bundled to form the core 6. Since the low-temperature flexible cable 1 is formed by forming the sheath 4 having a braided structure made of, the heat radiation in the freezer can be minimized to a minimum and sufficient flexibility can be obtained even at a low temperature of -50 ° C or lower. Can be maintained.

Further, since the sheath 4 is formed by braiding the soft copper wire, the core 6 can be shielded from the outside, and furthermore, the electric shock can be prevented.

Although polyethylene is used as the insulating cover, the present invention is not limited to this, and another resin material such as Teflon or polyurethane having the same flexibility as polyethylene may be used.

The sheath 4 may be made of tetron yarn or carbon fiber instead of soft copper wire. The flexibility of the low-temperature flexible cable 1 can be further increased, and the cable can be manufactured at low cost.

Although the insulated conductors 3 are twisted and bound, they may be simply assembled and bound.

Another embodiment will be described.

The low-temperature flexible cable 10 shown in FIG. 2 is obtained by changing the sheath 4 of the low-temperature flexible cable 1 shown in FIG.

The sheath 11 of the low-temperature flexible cable 10 is
An inner layer 12 formed directly on the outer periphery of the core 6;
And an outer layer 13 formed on the outer periphery of the inner layer.

The inner layer 12 is formed by braiding polyamide fibers (nylon yarn), which are cold-resistant fibers, so as to protect the core 6 against an externally applied impact force.

The outer layer 13 is formed by braiding a soft copper wire as a metal so as to shield the inner layer 12 and the core 6 from the outside.

The operation will be described.

When the low-temperature flexible cable 10 is bent,
The insulated conductor 3 forming the core 6 is bent while freely moving in the inner layer 12, the polyamide fiber forming the inner layer 12 is bent while moving the interval between the fibers, and the outer layer 13 is bent while moving the interval between the soft copper wires. Be bent. At this time, the core 6 and the inner layer 12 and the inner layer 12 and the outer layer 13 are bent while being shifted, and are easily bent.

As described above, the sheath 11 is formed in two layers,
One of the layers (outer layer 13) is formed of soft copper wire,
Since the other layer (inner layer 12) is formed of polyamide fiber, a layer braided with soft copper wire can have a function as a shielding layer, and a layer braided with polyamide fiber has a function as a protective layer. Can be made.

Further, by forming the layer (inner layer 12) with polyamide fiber, it is possible to form a heat insulating layer that hardly circulates air inside the low-temperature flexible cable 10,
A small amount of heat generated from the core 6 at the time of energization can be kept inside, heat radiation to the freezer can be prevented, and the insulation-coated conductor 3 can be kept warm to further enhance the flexibility of the low-temperature flexible cable 10.

Although the braid made of polyamide fiber is arranged on the inner layer 12 and the braid made of soft copper wire is arranged on the outer layer 13, the present invention is not limited to this.
2 may be provided with a braid made of annealed copper wire, and the outer layer 13 may be provided with a braid made of a polyamide fiber.

The soft copper wire may be replaced with tetron yarn or carbon fiber.

Another embodiment will be described.

The low-temperature flexible cable 20 shown in FIG. 3 is obtained by changing the sheath 4 of the low-temperature flexible cable 1 shown in FIG.

The sheath 21 of the low temperature flexible cable 20 is
It is braided (cross-woven braid) by blending a soft copper wire as a metal wire and a polyamide fiber.

Since the sheath 21 is formed by blending a soft copper wire and a polyamide fiber, good flexibility can be obtained, shielding can be obtained, and the sheath 21 can be manufactured at low cost. be able to.

The soft copper wire may be replaced with tetron yarn or carbon fiber.

[0043]

In summary, according to the present invention, the following excellent effects can be obtained.

(1) The heat radiation in the freezer is small, and
Sufficient flexibility can be maintained even at a low temperature of not more than ℃.

[Brief description of the drawings]

FIG. 1 is a sectional view of a low-temperature flexible cable showing a preferred embodiment of the present invention.

FIG. 2 is a sectional view of a low-temperature flexible cable according to another embodiment.

FIG. 3 is a sectional view of a low-temperature flexible cable showing another embodiment.

FIG. 4 is a cross-sectional view of a conventional low-temperature flexible cable.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Low-temperature flexible cable 2 Conductor 3 Insulated covering conductor 4 Sheath 6 Core 10 Low-temperature flexible cable 11 Sheath 12 Inner layer (the other layer) 13 Outer layer (one layer) 20 Low-temperature flexible cable 21 Sheath

 ────────────────────────────────────────────────── ─── Continuing from the front page (72) Inventor Masahide Iinuma 5-1-1, Hidaka-cho, Hitachi-shi, Ibaraki F-term in the Hidaka Works of Hitachi Cable, Ltd. (reference) 5G311 AB03 AC05 AD02 AD03 5G313 AB02 AB05 AB08 AC07 AD06 AE01 AE05 AE08 AE10

Claims (3)

[Claims] 1. A low-temperature flexible cable which is bent at a low temperature of -50 ° C. or lower, insulates a conductor to form a plurality of insulated conductors, and bundles the insulated conductors to form a core. A low-temperature flexible cable characterized in that a braided sheath made of a cold-resistant material such as metal is formed on the outer periphery of the core. 2. The low-temperature flexibility according to claim 1, wherein the sheath is formed in two layers, one of which is formed of a metal wire, and the other is formed of cold-resistant fiber made of polyamide fiber or the like. cable. 3. The low-temperature flexible cable according to claim 1, wherein the sheath is formed by blending a metal wire and a cold-resistant fiber made of a polyamide fiber or the like.